WickE350

Im currently in the middle of replacing the chain tensioners and installing check valves. I have the right side (passenger) done. Timing was 40 degrees past tdc while doing this side. But I cannot find any information about the engine position for doing the left side (driver).

CaliBenzDriver

... honestly: dont sweat it. Nothing is going to happen.

I swapped my tensioners as-is regardless of TDC crankshaft position because I did not have the jumbo socket No1.

The tensioner has just a weak automatic spring. No big deal unlike when pisitioning timing gears.

The tensioners are just holding back the chain slack from allowing start-up rattle.

BlackML550

Were you getting any rattle at all? Not just on start up, but occasionally under load?

WickE350

I was only getting rattle on cold starts with no cel

BlackML550

Thanks. Am interested if the new tensioners are the fix for you. Good luck

WickE350

UPDATE! The engine needs to be rotated about another 20-40 degrees to relax the chain on the driver side of the engine. I manually kept tension on the tensioner arm and slowly rotated the engine until it loosened up enough to get the new chain tensioner on

S-Prihadi

Interesting....
I thought the chain tensioner is a constant pressure device ?..... but maybe engine off no oil pressure ?

WickE350

I had removed the old tensioner before I rotated the engine which was a struggle due to the chain still being very tight. With that old tensioner removed the chain was still too tight to put the new tensioner in. I applied pressure to the arm while I rotated the engine just to avoid jumping timing. I highly recommend rotating the engine before removing the old tensioner.

Ultrakla$$ic

I'm contemplating on putting the ant-drain valves in my M278 engine. All of the videos show installation on the passenger side where pressing the ant-drain valve in looks easy because of the amount of clearance. What about pressing the anti-drain valve into the DRIVERS side head with the oil filter housing in the way???? Possible without removing the oil filter housing to put the anti- drain back press tool in place to press in anti-drain valve without removing the whole oil filter housing??? Thanks

WickE350

you don’t need to remove the housing. Just the filter. The tool is pretty small. I had no problems installing the check valves. Just make sure to cover up the housing so nothing falls in there

Baltistyle

correct, the engine should be rotated before the tensioner is removed, or it can get very tight in there. I had a very hard time getting my tensioner out because of the chain tension. Then, rotating the engine without that tensioner could cause the chain to slip and cause lots of problems. There is info on here about the exact proper procedure, but I don’t know exactly where to point for you unfortunately.

from my experience, check valves and tensioners fixed a one second rattle that would only happen after the car sat for a week. Ive not had the rattle since install, years ago.

Baltistyle

This is true of the 278. It is not true for the m157. The 278 has the smaller filter housing and different routing.

this statement is for future readers and is well covered in the cam magnet thread. M157, no easy way about it.. on the driver side.

Ultrakla$$ic

Thank you soooooooooooo much for the quick reply and for this thread!



Thank you for the insight!

Ultrakla$$ic

Ok, I've watched a ton of videos and it seems like just nuts and bolts to me, HOWEVER, putting the engine in correct timing "should" make taking out/installing the tensioners a bit easier.

So just to recap so I understand this, starting on the passenger side, should the engine be at the 40* timing mark to create the least amount of force on the timing chain for tensioner/anti-drain valve replacement?

THEN rotate to 53* timing mark to do the drivers side and repeat the removal/install process???

sorry for the obnoxious questions but I don't want to have to force anything to come out because I've got the chains in a bind out of ignorance. TIA

BlackML550

40 degress is the setting to align all the components when the chains need to come off. Theoretically, I can't see how any point in the chain's movement should make a difference to the chain tensioner - and I stress, theoretically. Its not as if there is a soft point at 40 degrees where the tension that is required, changes for this or some other purpose.

Not to suggest you shouldn't do it anyway. if you do run into a problem, at least you know the position of everything.

WickE350

yup. Do the passenger side first with the timing set at 40 past tdc. Then you need to rotate the engine another 20-40 degrees (I wasn’t sure of the exact position because there are no marks after 53) just keep an eye on the chain tensioner you should see the chain start to loosen up. Then remove the tensioner and repeat the process

WickE350

So this did not fix my rattle issue. It seems like it is better but still there. What’s the next step?

CaliBenzDriver

New tensioners with check valves still rattling....
Your new tensioners will serve you extremely well soon.


We can guess VVT Gear may be unlocked thus rattling.
With the same crank pulley wrench, rotate engine CW while listening for camshaft launching forward unlocked -

> We are trying to prevent having to remove parts soly for inspections.

If you can't hear the caracteristic "TIC" simply remove 4x CPS sensors to observe rotating camshaft motion.

I think I only know two sources of start-up rattling: tensioners + VVT both courtesy of the HPFP on passenger side Bank1 intake.
Actually old oil viscosity helps make this worse as well until oil get pumped up. Good oil viscosity does not drain down too fast.

NOTE: GRANTED once after installing new tensioners engine rattles 1st class until tensioners have no air left inside.

Baltistyle

what type of oil and how much have you driven it since. Different vehicle but I’m really fond of motul. Mobil one is just too thin, for every car I’ve ever tried it in, it’s junk.

CaliBenzDriver

I couldn't agree more for the most part. It counter intuitive to those with the "best or nothing in their mind.
Do you that we are currently testing the very fix for thin oil?
It's a $5 addition of some amount of 15w-50 in existing sump oil below max.

modern oil want to lubricate using additives with low viscosity film. The solution is a booster-shot in compatible base oil.
MOTUL is one of my current favorite 5w40

WickE350

I use liqui moly. And I’ve put about 20 miles on it since I did the check valves and tensioners

Baltistyle

my evolution before checkvalves and tensioners on my 157 was Mobil one to liquimoly with mos2 and ceratec to motul with mos2 and ceretec. After tensioners etc I stick with the motul combination. 5k miles is a long interval for me and I usually change sooner.

I did get rattle one time on startup after doing the work, and it was a few days later. But I’ve never heard one since no matter how long the car sits winter or summer.

I know the engines are different but the theories are the same hence the interest in the oil control valves. We need more pressure, likely best achieved with a little viscosity like Calibenz said. Funny because all of the old additives for turbo cars or “fixes” in a bottle were usually a very thick oil to be added in small amounts, by volume to your normal oil.

DeanMassy

I thought the chain tensioner is a constant pressure device ?..... but maybe engine off no oil pressure ?

kajtek1

I advise to get copy of WIS for such jobs.
Some engine models calls for tensioner shortening before installation and owners doing it without WIS, forced them in, destroying engine as the result.
So maybe 40 degree set is needed, maybe not, but without WIS we can only talk.

Baltistyle

As stated, it’s in the m157 check valves and tensioners thread. Something like the third post.

https://mbworld.org/forums/w212-amg/...ck-valves.html